A food contains 5 grams of carbohydrates, 10 grams of fat, and 5 grams of protein. How many calories (kcal) does this food provide?
The Correct Answer and Explanation is:
To determine the total caloric content of the food item, we need to know the caloric value of each macronutrient: carbohydrates, fats, and proteins. The caloric values are as follows:
- Carbohydrates: 4 calories per gram
- Fats: 9 calories per gram
- Proteins: 4 calories per gram
Given the amounts in the food item:
- Carbohydrates: 5 grams
- Fats: 10 grams
- Proteins: 5 grams
We can calculate the total calories from each macronutrient using the following formulas:
- Calories from Carbohydrates = grams of carbohydrates × calories per gram of carbohydrates
[
= 5 \text{ grams} \times 4 \text{ kcal/gram} = 20 \text{ kcal}
] - Calories from Fats = grams of fats × calories per gram of fats
[
= 10 \text{ grams} \times 9 \text{ kcal/gram} = 90 \text{ kcal}
] - Calories from Proteins = grams of proteins × calories per gram of proteins
[
= 5 \text{ grams} \times 4 \text{ kcal/gram} = 20 \text{ kcal}
]
Next, we add the calories from all macronutrients to get the total caloric content of the food:
[
\text{Total calories} = \text{Calories from carbohydrates} + \text{Calories from fats} + \text{Calories from proteins}
]
[
= 20 \text{ kcal} + 90 \text{ kcal} + 20 \text{ kcal} = 130 \text{ kcal}
]
Thus, the food provides 130 calories (kcal).
Explanation of Macronutrients and Their Caloric Contribution
Macronutrients are essential nutrients that provide the energy necessary for bodily functions. Carbohydrates and proteins each provide 4 calories per gram, while fats contribute significantly more at 9 calories per gram. This variance in caloric density is important when considering dietary choices, as fat-rich foods can contribute to a higher caloric intake even in small servings.
In this example, while the food contains equal grams of carbohydrates and protein (5 grams each), the substantial amount of fat (10 grams) is what largely increases its total caloric value. Understanding these values can help individuals manage their dietary energy intake, whether for weight loss, maintenance, or muscle gain. Knowing how to calculate the caloric content based on macronutrient composition is a valuable skill in nutrition, helping guide healthier food choices.